Hi all,
if for example I had a variable containing the string 'hello', is the any way I can output, for example, the e and the 2nd l based on their position in the string not their character (in this case 2 and 4)?
any general pointers in the right direction will be much appreciated, at... (3 Replies)
Hi Please help me to refine my syntax. I want to delete the excess characters from the out put below.
-bash-3.00$ top -b -n2 -d 00.20 |grep Cpu|tail -1 | awk -F ":" '{ print $2 }' | cut -d, -f1
4.4% us
now i want to delete the % and us. How wil i do that to make it just 4.4.
Thanks (7 Replies)
Hi,
I've a csv file seperated by '|' from which I'm trying to remove the excess '|' characters more than the existing fields. My CSV looks like as below.
HRLOAD|Service|AddChange|EN
PERSONID|STATUS|LASTNAME|FIRSTNAME|ITDCLIENTUSERID|ADDRESSLINE1
10000001|ACTIVE|Testazar1|Testore1|20041|||... (24 Replies)
sed -e "s// /g" old.txt > new.txt
While I do know some control characters need to be escaped, can normal characters also be escaped and still work the same way? Basically I do not know all control characters that have a special meaning, for example, ?, ., % have a meaning and have to be escaped... (11 Replies)
helloo
I wonder if there's a way to cut characters out of a string and keep only
the last 2 by using sed.
For example if there's the todays' date:
2012-05-06
and we only want to keep the last 2 characters which are the day.
Is there a quick way to do it with sed? (2 Replies)
Hey guys,
I know that title is a mouthful - I'll try to better explain my struggles a little better...
What I'm trying to do is:
1. Query a db and output to a file, a list of column data.
2. Then, for each line in this file, repeat these values but wrap them with:
ITEM{
... (3 Replies)
Hi,
I have a xml file (Config.xml)
<Header name="" TDate="" PDate="">
<Config>
{"config" { "Nation" "Pri:|Sec:"}}
</Config>
</Header>
Now I wanted to printed all the strings between "". I tried the following
cat Config.xml | sed -n 's/.*\.*//p'
... (8 Replies)
Hi,
I hope you can help me out please?
I need to replace from character 8-16 with AAAAAAAA and the rest should stay the same after character 16
gtwrhtrd11111111rjytwyejtyjejetjyetgeaEHT
wrehrhw22222222hytekutkyukrylryilruilrGEQTH
hrwjyety33333333gtrhwrjrgkreglqeriugn;RUGNEURGU
... (4 Replies)
I have a file that looks like this:
>ID 1
AATAATTCCGGATCGTGC
>ID 2
TTTGACAGTAGAC
>ID 3
AGACGATGACGAT
I am using the following script to report if AATTCCGGATCG is present in any sequence:
awk 'FNR==1{n=substr(FILENAME,1,index(FILENAME,".")-1)} { print n "\t"... (10 Replies)
Discussion started by: Xterra
10 Replies
LEARN ABOUT DEBIAN
io::handle::prototype::fallback
IO::Handle::Prototype::Fallback(3pm) User Contributed Perl Documentation IO::Handle::Prototype::Fallback(3pm)NAME
IO::Handle::Prototype::Fallback - Create IO::Handle like objects using a set of callbacks.
SYNOPSIS
my $fh = IO::Handle::Prototype::Fallback->new(
getline => sub {
my $fh = shift;
...
},
);
DESCRIPTION
This class provides a way to define a filehandle based on callbacks.
Fallback implementations are provided to the extent possible based on the provided callbacks, for both writing and reading.
SPECIAL CALLBACKS
This class provides two additional methods on top of IO::Handle, designed to let you implement things with a minimal amount of baggage.
The fallback methods are all best implemented using these, though these can be implemented in terms of Perl's standard methods too.
However, to provide the most consistent semantics, it's better to do this:
IO::Handle::Prototype::Fallback->new(
__read => sub {
shift @array;
},
);
Than this:
IO::Handle::Prototype::Fallback->new(
getline => sub {
shift @array;
},
);
Because the fallback implementation of "getline" implements all of the extra crap you'd need to handle to have a fully featured
implementation.
__read
Return a chunk of data of any size (could use $/ or not, it depends on you, unlike "getline" which probably should respect the value of
$/).
This avoids the annoying "substr" stuff you need to do with "read".
__write $string
Write out a string.
This is like a simplified "print", which can disregard $, and "$" as well as multiple argument forms, and does not have the extra
"substr" annoyance of "write" or "syswrite".
WRAPPING
If you provide a single reading related callback ("__read", "getline" or "read") then your callback will be used to implement all of the
other reading primitives using a string buffer.
These implementations handle $/ in all forms ("undef", ref to number and string), all the funny calling conventions for "read", etc.
FALLBACKS
Any callback that can be defined purely in terms of other callbacks in a way will be added. For instance "getc" can be implemented in terms
of "read", "say" can be implemented in terms of "print", "print" can be implemented in terms of "write", "write" can be implemented in
terms of "print", etc.
None of these require special wrapping and will always be added if their dependencies are present.
GLOB OVERLOADING
When overloaded as a glob a tied handle will be returned. This allows you to use the handle in Perl's IO builtins. For instance:
my $line = <$fh>
will not call the "getline" method natively, but the tied interface arranges for that to happen.
perl v5.10.1 2009-09-29 IO::Handle::Prototype::Fallback(3pm)